Manufacture of nickel carbonyl



Patented June 10, 1941- I 2,245,503 MANUFACTURE or mcxar. caaaom LeoSchlecht, Rudolf Staeger, and Herman Klippel, Ludwigshafenon the Rhine,Germany, assiznors to I. G. Farbenindustrle Aktiengesellschaft, GermanyFrankfort on the Main,

No Drawing. Application March 2, 1939, Serial In Germany March 12, 19382 Claims. (Cl. 23-203) The present invention relates to improvements inthe manufacture of nickel carbonyl.

In the working up of nickel-copper matte for the recovery of nickelcarbonyl, the ground matte has hitherto first been roasted until thesulphur has been removed as far as possible and the major portion of thecopper then dissolved out with sulphuric acid from the roasted product.The nickel residue poor in copper is then reduced with watergas at about400 C. and finally treated with carbon monoxide, the formation of nickelcarbonyl thus taking place. I

In'the said process, the major portion of the copper must be removed bya special working operation. In order to avoid this drawback it has beenproposed to use for the formation of carbonyl a matte of which thesulphur content has been reduced to such an extent in the smeltingprocess by blasting that'in the smelted product at the most only thecopper, in the form of cuprous sulphide, is combined with sulphur. Sucha blasting process, however, causes waste of nickel.

by slagging.

Finally, attempts have also been ,made to reduce the original highsulphur content of nickelcopper mattes by admixture of finely dividedmetal, such as copper or iron powder. Considerable additional costs areoccasioned, however, in the provision of the admixed metal in thenecessary finely divided form. It has therefore been proposed to roastthoroughly 9. part of the matte,

or by reduction with gases in arotary tubular furnace. When carrying outthe reduction in a way causing a furtherdecrease of the sulphur contentleft behind in the roasting stage, care should be taken that acorrespondingly higher amount of sulphur remains in the roasting stage.

If the formation of carbonyl be carried out I under pressure, it isadvantageous also to carry to mix it with another part of the unroastedmatte,

to reduce the mixture and then to subject it to the treatment withcarbon monoxide for the purpose of forming carbonyl. In this latterprocess, however, it is necessary to reduce as far as possible thesulphur content of the part to be roasted and this offers technicaldifliculties.

We have now found that all the said difliculties can be avoided bydecreasing the sulphur content of the whole amount of matte, withoutprevious removal-of the copper to such an extent by roasting that thecopper and/or iron content of the roasted product is sufficient forbinding the remalning amount of sulphur, reducing the partially roastedproduct and then subjecting it to the carbon monoxide treatment for thepurpose of forming carbonyl.

The roasting, which is preferably carried out at about 800 0., offers nodiilicul-ties because only the amount of sulphur which is most easilyroasted off is to be removed.

The reduction of the roasted product may be carried out in differentways, for example by' fusing the mixture with carbon in a flame furnaceout the reduction in the same pressure container under increasedpressure with gases such as hydrogen. Very low temperatures, as forexample 250 C., may be used, whereby a good reactivity of the nickel forthe reaction with carbon monoxide to form nickel carbonyl is ensured.

Nickel-copper mattes of any constitution, in-

cluding those having a very high sulphur con-,

tent, maybe used as initial materials. Iron may ing should be carried sofar that the ratio of iron to sulphur in the roast product is the sameas in iron monosulphide. 'Thus, when workingaccording to our invention,the sulphur contained in the roasted and reduced product which is to betreated with carbon monoxide to form carbonyl, is in any case combinedwith copper and/or iron to sulphide, may be in the form of cuproussulphide or of iron monosulphide or of both sulphides.

The following examples will further illustrate how the present inventionmay be carried out in practice, but the invention is not restricted tothese examples.

Example 1 Nickel-copper matte having a content of 44.6 per cent ofnickel, 33 per cent of copper, 0.6 per cent of iron and about 21 percent of sulphur is roasted until the sulphur content has fallen to about3 per cent. The roasted product is then treated in a high pressurefurnace with flowing hydrogen in a cycle under a pressure of 200atmospheres at 240 C. until no water separates when the hydrogen leavingthe furnace is cooled. The hydrogen pressure is then allowed to subsideand the temperature in the high pressure furnace is allowed to fall toabout 100 C. At this temperature carbon monoxide is allowed to flow intothe furnace and the pressure of the carbon monoxide is slowly raised to200 atmospheres and the temperature to about 200C. The nickel carbonylformed is separated in liquid form from v the gas leaving the furnace bycooling and the roasted product is converted into nickel carbonyl.

Example 2 Nickel-copper matte having a content of 47.28 per cent ofnickel, 26.07 per cent of copper, 2.57 per cent of iron and 22.4 percent of sulphur is roasted until it contains 39 .8 per cent of nickel,21.85 per cent of copper, 2.16 per cent of iron and 4.26 per cent ofsulphur. The mass is then treated with a stream of hydrogen at 240 C.under a pressure of 200 atmospheres and then treated with a stream ofcarbon monoxide at 220 C. under the same pressure. About 95.3 per centof the nickel contained in the roasted product is converted into nickelcarbonyl.

If the said nickel-copper matte be roasted until it contains 39.24 percent of nickel, 21.6 per cent of copper, 2.15 per cent of iron and 7.8per cent of sulphur and the roasted product be treated with hydrogen andcarbon monoxide under the above mentioned conditions, only about 83.3per cent of the nickel contained in the roasted product is convertedinto nickel carbonyl.

What we claim is:

1. A process of producing nickel carbonyl from nickel matte containingsulfur and at least one of the metals iron and copper which comprisesroasting the matte until sulfur is removed to such an extent that themetal content of the roasted matte of at least one of the metals ironand copper is sufiicient to bind the remaining amount of sulfur,reducing the partially roasted product with hydrogen under substantialpressure and directly subjecting the roasted and reduced product tocarbonylization by treatment with carbon monoxide.

2. A process of producing nickel carbonyl from nickel matte containingsulfur and at least one of the metals iron and copper which comprisesroasting the matte until sulfur is removed to such an extent that themetal content of the roasted matte of at least one of the metals ironand copper is suflicient to bind the remaining amount of sulfur,reducing the partially roasted product at about 250 C. with hydrogenunder substantial pressure and directly subjecting the roasted andreduced product to carbonylization by treatment with carbon monoxide.

LEO SCHLECHT. RUDOLF STAEGER. HERMANN KLIPPEL.

